1. Field of the Invention
The present invention relates to a method for communicating between a first motor vehicle and at least one second motor vehicle in a mobile communication network comprising at least two motor vehicles.
2. Description of Prior Art
The field of application of the invention relates to a so-called vehicle-to-vehicle communication, which is also called “car-to-car communication”, and manages completely without stationary communication nodes. Such communication networks are used today mainly in commercial vehicles which are in a column formation in order to transport goods from a departure location to a common destination. The communication accompanying this transport task allows simple coordination of the individual vehicles during the trip. Thus, traffic disturbances, planned trip interruptions and the like can be communicated between the vehicles during the trip.
Modern vehicles are frequently equipped with keyless access systems or radio keys called Remote Keyless Entry (RKE). These radio keys control the locking and unlocking of doors and boot of a motor vehicle by radio control. In this manner, the vehicle door locks of a motor vehicle can be opened or closed wirelessly. Other functions can be activated or deactivated via radio keys such as the immobilizer.
A radio key system comprises a receiver at the vehicle and or a vehicle module, respectively, and one or more mobile transmitters, which can be held in one's hand. The transmitter or the portable module can be provided with one or more manually operable switches. Furthermore, they are radio keys of more recent generations in the case of which the radio key is no longer taken in one's hand but the transmitter at the vehicle end registers the closeness of the key to the vehicle and unlocks the door lock, for example due to the door handle being touched by the driver. Dispensing with manual inputs via the radio key transmitter becomes possible using so-called bidirectional communication. Differently from a conventional radio key central locking system, the radio key transmitter sends not only signals to the locking system but also it receives information from the locking system. In this context, the radio key transmitter is constructed as a transceiver. With passive start and entry (PA-SE), the doors become unlocked by touching the door handle alone, and the engine can be started without a key by button pressure. In this context, the transceiver at the vehicle end has a memory that stores an identification code that can identify the radio key transmitter.
The exchange of information with various vehicles which participate in the traffic, and between vehicle and infrastructure, can contribute to an increase in the safety of the road users and in the comfort of the vehicle drivers. This communication from vehicle to vehicle or from vehicle to infrastructure, which will be called vehicle-to-X communication (C2X communication) in the text that follows can only be utilized if a certain proportion of the vehicles or infrastructural units involved is equipped with corresponding communication units based on the same technology. The rapidly changing communication technology and in dependence on the price expectations of the vehicle drivers, the additional expenditure for providing and installing such a communication unit, associated with the upgrading of the vehicles, can be too high. Therefore, simple and cost-effective solution options are needed which will make vehicle-to-X communication available for many vehicle owners.
In JP 2005174237 A, a familiar system for communication between vehicles of a communication network is found based on the broadcasting principle. In this arrangement, the driver of a vehicle can transmit by radio telephony information which can be received by other vehicles. For this purpose, a radio communication frequency, on which the voice communication is to take place, must first be specified between the vehicles. As an alternative, it is also conceivable to exchange the information on a general voice channel, the affiliation with a certain communication network being transmitted by an identity information item initiating the voice communication. The solution presented in this prior art is mainly dedicated to measures for eliminating communication disturbances during the vehicle-to-vehicle communication.
In DE 10 2005 013 648 A1, a further system for communication between vehicles of a communication network is found. A first motor vehicle or a stationary network node sends out beacons that comprise at least one information item about the position of the first motor vehicle or of the stationary network node, a time interval between two beacons sent by the first motor vehicle being set in dependence on the speed of the first motor vehicle, the number of motor vehicles belonging to the communication network within the receiving range of the first motor vehicle or of the stationary network node, the position of the first motor vehicle, the time and/or the condition of the first motor vehicle or of the stationary network node. In this context, communication between individual motor vehicles in the communication network takes place entirely without the necessity of stationary communication nodes.
It is also provided that the communication between the motor vehicles not located within mutual receiving range takes place by a suitable routing method via further motor vehicles of the communication network. This is preferably carried out via WLAN or by using known Internet protocols. Initiating the internal communication requires setting up a connection corresponding to the communication technology.